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I noticed that the Netroots Nation website links to the Burnt Orange Report’s Guide to Visiting Austin. Number one on the list of things to do is swimming at Barton Springs Pool.
Barton Springs is indeed a very special place. It’s also a very visible reminder of one of the most unique and fragile geological features in Central Texas – the Edwards Aquifer.
Follow me over the fold to learn more about this special resource, and how you can help protect it during and after your visit to my hometown.
Central Texas is a land of limestone. The chalky white, fossil-riddled rock is everywhere – it’s what you build your house with and dig up out of the yard. It channels beautiful rivers and forms amazing swimming holes. It also makes possible the Edwards Aquifer -- a prolific groundwater system that provides water to more than two million people in south central Texas.
Some basic geology
The Edwards Aquifer is essentially a tilted layer of fractured limestone. Most of it is sandwiched between impermeable rock layers, but a section of Edwards limestone outcrops (i.e., reaches the surface) in a narrow, 160-mile-long strip of land arcing south and west from Austin. This is the recharge zone, where surface water enters the aquifer.
Water then flows through the porous limestone into the artesian zone, where impermeable rock layers confine the water. The weight of incoming water creates enough pressure to force water up through wells and faults. These artesian wells and natural springs feed into rivers and estuaries, support rare species (such as the endangered Barton Springs salamander), and supply clean water to San Antonio and smaller towns to the west and north. (Just how clean is the water? Except for required chlorine for the pipes, San Antonio doesn’t treat its water at all!)
Threats to water quality
As long as the recharge zone and the watersheds that flow into it are protected, the aquifer should continue providing clean water. Major contamination would be difficult if not impossible to remedy, and San Antonio would be forced to begin treating its water supply. There are tensions between conservation and development interests, but having grown up near Austin I will tell you that most Central Texans I know are aware of and care about the aquifer, and do their best to be good stewards.
Threats to water quantity
The first and most visible threat to water quantity is simply the amount of water use – for sustainable supply, you can only take out as much as flows in. As the area’s population grows, water conservation is increasingly important.
In fact, right now, the Barton Springs segment of the aquifer is in Alarm Stage Drought and users are being asked to reduce water use 20 percent. Of course, humans aren’t the only ones feeling the pinch – delicate ecosystems and wildlife are also affected.
A second concern is climate change. One study concluded that, even if water use remains steady over the next few decades (implying ever higher water use efficiency), climate change could "severely impact" water resources in the Edwards Aquifer region. This, of course, will be expensive. Another study of the aquifer estimated that climate-induced water shortages could cost millions of dollars a year.
What can we do?
Everyone can help minimize these risks. You’ll notice that all of these actions are good to do wherever you are, but a visit to such a special place is worthy of a special reminder!
- Whether you’re a full-time resident or a visitor to the Edwards Aquifer region, please use water responsibly. Added bonus: water efficiency is linked to energy efficiency.
- Remember that in the recharge zone – including Austin – any contaminants in surface water, such as oil from roads or pesticides from lawns, could end up in the aquifer.
- We need to reduce greenhouse gas emissions as soon and as steeply as possible.
So, welcome to Austin, y’all. I know you’ll love the food and enjoy the music. I hope you’ll also appreciate our invisible but indispensable Edwards Aquifer.
Further Reading
- The geology of the Edwards Aquifer is
VASTLY more complicated than I've described here.